In reality what is considered the total "immune system" consists of a lot more than what we, who are concerned with MS consider it, but in the field of MS the lymphocytes ARE the immune system and the bone marrow is the parent....the creator of the immune system.
I know, you have polynuclears, monocytes, and many others. But I think several immune cells are involved in MS, not only T cells. For instance, B cells are targeted by some treatments being tested, and it seems to work. (I don't remember which one, but I think it's in phase III) I agree when you say T cells are main "attackers" but I think they're not alone.
What you're talking about, a total reboot (or the attempt) has been used on luekemia since the 1960's and was based on the assumption that the MS process is also reciprocated in the bone marrow, which would also have to be eliminated and re-created. The total reboot was the first thing that came to the minds of researchers and it's what they were familiar with. In truth, the lead researcher in the Stony Brook cyclophosphamide study is an oncologist and not the expected neurologist.
I still hope some more studies will show that total reboot is possible, but I've seen it wasn't 100 % efficient so far, whereas one could think it would be. That's why researchers are worried : if you total reboot immune system, and if you completely rebuild bone marrow with "clean" stem cells, why is the disease still active with some patients ? No answers are provided, because few studies were made, beacause the process is dangerous. (5% death risk). Here are some hypothesis, some of them I found on the web, some of them coming from my own thoughts :
- Maybe Inflammation is stopped, immune attack is stopped, but axonal degeneration goes on. This make sense as study authors pointed out that immune and marrow reboot was performed with heavily handicapped patients, many of them with SPMS or fast PPMS, where axonal degeneration is suspected to be dominant. They say total reboot would be more efficient on patients with early, inflammatory RRMS, but it's far too risky for them.
- Maybe reset patients are exposed again to that unknown environmental trigger, and catch the disease a second time. (if it's linked to your lifestyle, you're likeky to be exposed again)
- Maybe there's another mechanism involving something else than immune system and bone marrow, and that mechanism is not affected by immune reboot.
- Maybe the reboot was not done properly with patients who still show disease activity (hope this is the good one)
Anyway, if it proves to be efficient, it would be a breakthrough. A breakthrough I'd like to see for my grilfriend before it's too late.
Because the preponderance of abstracts/studies DO NOT reflect the results of simple lymphocyte elimination, almost the easiest thing to do is to read the wrong information and come to an incorrect conclusion.
And those studies don't involve enough patients to have statistical coherent results...